1. Field of the Invention
The present invention relates to precharged ground coffee capsules, a method of production thereof, and an apparatus for implementing such method
2. Description of the Related Art
Precharged ground coffee capsules are gaining more and more importance in the market since they are easy and practical to be used, and because each single ground coffee dose assures for a better maintenance of coffee fragrance. Precharged capsules can be projected for both espresso coffee machines and moka type coffee machines or the like; in the last years, the shape and structure of the different capsules have been widely developed because of different use and preservation requirements.
In the choice of the materials and structure to be imparted to a precharged capsule, a considerable problem is to determine a right balance between strength and effectiveness in use; in other terms, if water-permeable materials such as filter paper, non-woven fabric and the like allow for a good utilization of the capsule on one hand, they have considerable drawbacks regarding to preservation and positioning of the capsule in a capsule-holder on the other hand.
The majority of commercially available precharged capsules follow two main veins: in one case, the main container body is made of a plastic material while, in the other case, the container body is made of a metallic material. In either cases, it is necessary to adopt special measures to solve several problems that hamper the production and/or use of the different precharged capsules. For example, capsules with a container body made of a plastic material can comprise certain materials which are adapted to resist the heat load, and generally they have to be molded, filled and than covered with layers of a water-permeable material. Capsules made of a metallic material are easy to be formed and require a very short thickness on one hand; on the other hand, they are difficult to be matched with a suitable filtering material, and they also have a drawback to react with ground coffee and speed up the development of rancidity. In most cases, in order to achieve good results from the point of view of preservation and preparation of a coffee brew, the device used with the precharged capsule has to be modified to an extent which can also be considerable, so that the precharged capsule can be pierced or otherwise fluid-communicated with means for supplying hot water under pressure and/or means for dispensing the ground coffee brew.
An aim of the present invention is to provide a precharged ground coffee capsule which does not compromise the preservation state of ground coffee while being of a simple and inexpensive construction, such capsule being easy to be used with both common espresso coffee machines and “moka type” coffee machines without any special modification to the coffee machine used with the precharged capsule.
Another aim of the present invention is a method for producing ground coffee precharged capsules, which method can be carried out in a simplest way using a single operating unit without transferring semi-finished products from a machine to another one.
Another aim of the present invention is to provide an apparatus for implementing such new method of production.